Samenvatting:In the period leading up to the climate conference in Copenhagen scientific evidence is mounting that deep reductions in greenhouse gas emissions, in industrialized (Annex I) countries as well as in non-industrialized (non-Annex I countries), are needed. In this study implications of achieving the lower end of the emission reductions necessary to stabilize atmospheric greenhouse gas concentration at 450 parts per million (ppm) CO2-equivalent are explored.
To bring global greenhouse gas emissions on a path to a low stabilization level which increases the chances that global mean temperature rise will be limited to 2 degree Celsius, Annex I countries would have to reduce their emissions by 25-40% by the year 2020, while non-Annex I countries need to substantially deviate from their emission baselines.
These 'substantial deviations from the baseline' of non-Annex I countries have been quantified in a recent paper to be in the order of 15-30% below their 2020 baseline emission levels. For Annex-I countries, an overall 30% emission reduction below 1990 levels is assumed for 2020. For the non-Annex I region in its entirety, emission reductions of about 15% below business-as-usual in the same timeframe are assumed, to be achieved by domestic mitigation efforts of the so-called 'emerging economies'.